The invention relates to a therapeutic system which comprises an ultrasound therapy unit (1, 518) arranged to insonify at least a portion of a body (2, 508) of a patient with high intensity ultrasound and a MR imaging unit (3, 500) arranged to acquire MR signals from the portion of the body (2, 508) and to reconstruct a thermographic MR image from the MR signals. It is an object of the invention to enable MR guided high intensity focused ultrasound (HIFU) treatment, in which temperature values within critical anatomic regions containing fat can be monitored. The invention proposes that the therapeutic system further comprises an ultrasound diagnostic unit (5, 518) which is arranged to acquire ultrasound signals from the portion of the body (2, 508) and to derive at least one local temperature value from the ultrasound signals.